Tires are the most important component of your bike. Supple high-end tires roll faster and are more comfortable. A set of great tires transforms your bike’s feel. The down side is that high-end tires can be more fragile than sturdy utility tires.

How durable are Grand Bois tires in particular? They have no problems on amazingly rough terrain – even the 32 mm-wide Cypres can handle almost any gravel road, and the wide Hetres (see above) work fine even in rocky terrain.

What about flats and tread wear?

Last year, I kept track of my mileage on a brand-new Grand Bois Cypres 700C x 32 mm tire. The tire was mounted on the rear, which carries the most weight and provides all the bike’s propulsion, so it gets about twice as much wear as the front.

I rode the tire for 4512 km (2820 miles) on the rear wheel until the tread became very thin. During this time, the tire had three flats. Two occurred in quick succession between kilometers 2500 and 3000. The third was on the tire’s last ride: I knew the thread was thin, but for the purposes of this experiment, I wanted to ride the tire until it got another flat. On the front, with an older tire of the same model, I had a single flat during this period. All these flats occurred on debris-strewn shoulders of major roads. I didn’t have any flats on the many miles of gravel and backroads that I rode.

While I don’t enjoy flat tires, fixing one every few months is a small price to pay for all of those days of better ride quality and higher speed. Besides, even “puncture-resistant” tires have flats once in a while.

If I had rotated my tires from front to rear to equalize wear, then my set of Grand Bois Cypres tires would have lasted about 6000 km (3750 miles). On a bike with fenders, rotating your tires and riding the more worn tire on the front is a good idea, as you easily can see that tire’s tread, whereas the rear tire tread is hidden inside the fender. Whether you rotate your tires or not, don’t ride your tire until the tread has worn down to the casing. You’ll get more flats as the tread gets very thin, and eventually, the tire will blow out with potentially dire consequences.

Wider tires last even longer, because they spread the wear over more rubber. Ryan’s Grand Bois Hetre tires lasted a bit over 8000 km (5000 miles) on all kinds of roads. (That is his tire in the photo above.) He did switch the worn rear tire to the front to equalize wear.

With the many hours of enjoyment I get out of a set of high-end tires, I consider the tires money well spent. At 25 km/h (16 mph), 6000 km represents 240 hours… so the additional cost of two high-end tires comes to about 30 cents an hour. If you want to save money on tires, get a bike designed for wider tires. Wider tires don’t cost much more, but they last significantly longer. They also provide an even better ride and get fewer flats.

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About Jan Heine, Editor, Bicycle Quarterly

I love cycling and bicycles, especially those that take us off the beaten path. I edit Bicycle Quarterly magazine, and occasionally write for other publications. One of our companies, Bicycle Quarterly Press publishes cycling books, while Compass Bicycles Ltd. makes and distributes high-quality bicycle components for real-world riders.

23 Responses to How Durable are Grand Bois Tires?

I had a set of Grand Bois 28mm tires that I destroyed in less than 300 km. I had one puncture in the front tire and two in back, including one that tore a hole through the tire, ruining it.

I hear about everyone else’s experience with Grand Bois tires and I’m jealous. They really were some of the nicest tires I’ve ever ridden. I’m sure I had some bad luck, but I also think that the combination of my weight and the pressure I needed to keep the relatively narrow tires at had something to do with it. I weigh about 200 pounds and I had the back tire pumped up to 105 PSI, which might be higher than these thin tires can handle. I imagine I’d have had a very different experience if I’d been running 45 mm tires at 60 PSI.

I don’t think the narrower versions of these tires are appropriate for heavier riders, but I can’t fit 32 mm tires on my bike with fenders, so I’ve moved on to Panaracer Paselas (which are made in the same factory as the Grand Bois) and I haven’t had a flat in 3000 km.

I can definitely see how wider tires would spread the weight over a greater surface area on uneven surfaces, but is that true on smooth roads? Seems intuitive, but I ask because I thought the elongated contact patch of narrow tires was the cause of their higher (theoretical) rolling resistance. Or is the compactness of a wider tire’s contact patch more important than its overall size?

I love my Gran Bois 700x32mm tires. But, I asked my friends this last week.
“What are we going to do about those Grand Bois tires? On the Oregon Coast 600 I flatted twice within 170km on 101, glass slash both times to a new rear tire.” My records show average of one flat every brevet on these tires.

Reading your article, it seems that the major highways are lethal to the fast tires, and for brevets using these routes a compromise solution with more flat protection is in order. Using the Panaracer T-Serv, I commuted 2o miles on debris strewn US 30 for a full school year having only one pinch flat in the dark before buying an Edilux. Is there a compromise solution in the Panaracer line between the T-Serv and Grand Bois for brevets in these conditions?

The Grand Bois “Hetre” 650B x 42 mm tires are amazingly flat-proof for most riders. I have had two flats in three years of urban riding on them. It’s probably a combination of the width – less pressure means that the tire can roll over debris without it cutting into the rubber – and perhaps the tread profile.

Beyond that, flat tires are random occurrences. I get a lot of reports from customers, and they either tend toward “Amazing, no flats in 3000 km” or “Got a flat rolling down the street on my first ride.” I sometimes go almost a year without flats, and then have three in a month…

Re: tire rotation – I prefer to use Sheldon’s method for tire rotation, i.e., when the back wears out I move the tire that had been on the front to the back and put a new tire on the front. It’s certainly true that doing this greatly adds to the service life of the tires.

Re: Cypres flats – I’ve never had one get slashed. Except for a hideous month of mystery rim-side flats that disappeared when I replaced the tubes, and a couple of bulletin board tacks that somehow found their way onto the road and into my tires, my flats on these tires always seem to be caused by tiny pieces of glass or tiny arrow head-shaped pieces of stone that looks like quartz to me.

I agree with your assessment that the ride quality and speed of the tires makes up for their higher incidence of flat tires. From November or December until sometime in spring (this year, it was last week), I remove the Grand Bois and switch to Paselas. They’re similar in feel, although slower — which doesn’t matter much during the “off season” — but are more flat resistant, longer wearing and much less expensive. And this year, as happened last year, when I removed the Paselas I was very surprised on the first ride to discover how much faster I had suddenly become.

when the back wears out I move the tire that had been on the front to the back and put a new tire on the front.

That works with racing bikes, but having the worn tire on the rear can be a problem with fenders. The rear tire already wears faster, and now you put the more worn tire on the rear, where you rarely look at its tread. The front tire is almost new, while the rear can wear through the casing before you know it.

That might be true if I rarely looked at the tread. However, I put my bikes up on a work stand every time I clean and re-lube the chain, which I do every 100-120 miles; and on the stand, the bike is high enough that the tread on the back tire is quite visible even with long fenders.

Actually, the only time I’ve actually worn through the tread on a tire was on the only bike I ride regularly that doesn’t have fenders. Back when Michelin’s top line 23mm racing tire had a green stripe in the center of the tread, I had the bike on the stand one day and noticed a black streak in the green center stripe and wondered – what is that, tar? I tried scraping it off with my thumbnail, and instead, the green center stripe peeled off.

The 40-584 Hetres ride well and have proven durable for both on- and off-road use, with no sidewall damage even on rocky trails, doubletrack, and mild technical singletrack.

Their ribbed tread doesn’t interlock well in snow, slush, or deep sand, but the Hetres handle high-speed cornering on pavement or gravel exceptionally well, both wet and dry.

Between June 2009 and January 2011, I put just over 3,000mi on my Hetres. Zero flat tires. The rear has worn through the tread ribs and started into the base rubber, but not yet worn thin. In comparison, I have around 1,500mi on the 127TPI Pacenti Paris-Moto, with five punctures to date, and a few hundred on the Ourson, with one puncture over the winter.

I’ve had zero flats to date on the Hetres, so I can’t comment on flat resistance other than to say they’re the most flat-resistant tires I’ve used as an adult. They’re excellent general use tires. I’ve got a set of Lierres on deck to test when the Hetres finally wear out.

Concerning rotation patterns, I rotate the front tire to the rear and put new tires on the front, even on my machines with fenders. I check tire wear whenever I oil my chain, which is frequent enough given the longevity of these tires.

You guys lube your chains more often than I do! I find that with front mudflaps, I rarely lube my chain after I install it. Often, the chain goes 1600 – 2000 km without lubrication, and then it’s time for a new one.

I used to lube often – maybe every 100-200 miles – when I was mostly just commuting on bikes. Now that I do a lot more long rides mixed in with the commutes, I find that I wipe the chain off every 100 miles or so to keep excess grit away, but I don’t apply more lube until it either starts to sound or feel less efficient. I’d guess that is closer to 300-500 miles depending on the season.

I’m surprised you go so long between lubes though, Jan. Doesn’t it start to get noisy? Do you have a special type of chain that doesn’t need lubrication somehow? I know if I went that long, I’d be replacing the cogs with the chain too, which is pricey without much benefit.

Chain lube doesn’t wear out, it gets washed off the chain by road spray. My front fenders are long and have mudflaps, so there is no spray onto the chain (or my feet) from my front wheel.

I once rode in heavy rain across the Ballard Bridge in Seattle, where water collects, and cars spray you constantly with water. Two days later, my chain squeaked terribly. All the lube had been washed off in less than half a mile of getting splashed. I was actually in Oregon documenting the Oregon Manifest, so I stopped at a grocery store and bought some oil.

So I lube my chain when it starts sounding dry or squeaky. Usually, that does not happen too frequently. (I also wipe the chain clean immediately after applying lube, so it attracts less dirt.)

Michelin offers a tire (admittedly not in a size that would be very exciting to this audience – 700 x 25) that has a separate version for front and back – the Pro Optimum. Michelin claims they have “optimized” both the wear and performance characteristics of the front and back versions – but the wear should be indentical (says Michelin), so you can buy a new set (front, back) of Pro Optimums and replace at one time.

The Michelin site states, “Built to be the ultimate long-distance road tire; Soft rubber compound on the front for added grip and safety; Special wear-resistant rubber mix on the rear for efficiency and durability; 25mm width front and rear for a smooth ride, plus high-density anti-puncture reinforcement.” It is sold alongside their high end clincher road tires such as the ProRace3 with similar pricing.

I have trouble not thinking of this as “we have downgraded the durability of the front tire to match the rear.” I wonder what their sales of these are like. If nothing else, it is a move to sell (very slightly) wider tires to the racing bike crowd.

VeloNews June 2011 has a vibration test where accelerometers were mounted on “endurance” bicycles (Specialized Roubaix the best of the group) and rolled the bike on Kreitler rollers on which had been welded a metal bar, either 1/8″ or 1/4″ square cross-section. They road-tested each bike with Michelin Pro Optimums, so at least the VeloNews staff apparently likes these.

The peak acceleration measured on the large bumps (1/4″) was reduced by 3.03g to 2.68g (LaPierre Sensium) and from 2.76g to 2.38g (Cannondale Synapse), in each case with tires at 90 psi. These are considerable reductions considering that wide with wide bumps the tire is less able to use its width to “average” out the road surface, and that the advantage of wide tires in allowing lower pressures was unexploited. So you’d expect on typical roads the advantage of the wider tire would be even greater.

And that’s only for a 2 mm increase in tire width….

The Specialized Roubaix, BTW, was considerably better than the other three bikes at large bumps, even relative to the advantage of the wider tires. But Jan already showed that just differences in fork design can yield substantial differences in power required to ride rumble strips. I’m sure accelerometer data would support the same conclusions.

1600-2000 km is no mileage at all. I typically get 6,000 miles or more on chains, and the last three I replaced still showed no measured elongation at that time. I replaced them because they’d gotten so loose sideways the rollers fell out of the end links.

I have about 1300 miles on my Grand Bois Cypres tires. I had two flats, one on the front and one on the back, right after each other last week during a 1200k ride. Many people asked how many flats I had, assuming it was many. But, 2 flats over that distance isn’t too bad in my mind. Especially considering there are few 700c options at the 32mm+ width. Depending on how end performance is on the Cypres, I may try the Pasela Tourguards….

Contrast that with the guy I rode the 1200k with. His 700cx28mm Gatorskins had 3 flats during the ride. One came while he was riding close to the fog line late one night and there was a good size (1/4″) rock he ran over. Moral of the story: regardless of which tire one uses, don’t run over debris. We all know that, but I don’t always see people practicing it for some odd reason.

I use to ride Roll-y Pol-y tires as my main tire. They were a bit more puncture-resistant than the Grand Bois. However, we were surprised how slow they were in our tests of rolling resistance. I was even more surprised how much my times in events improved once I switched to faster tires. The Jack Browns use the same casing, but in a wider width. We tested the 650B version, the Maxy-Fasties, and they also were relatively slow. (The first Grand Bois tires also disappointed in those tests. We worked with Grand Bois to improve their performance and comfort based on these tests…)

The Hetre rolled down our test hill in 27.3 seconds. The Maxy-Fasty took 29.8 seconds. That is a difference of 2.5 seconds – more than 10%. For the full results, see Bicycle Quarterly Vol. 5, No. 1 (Maxy-Fasty) and Vol. 6, No. 1.

Grand Bois tires are more hand-made than most tires, and the lightweight, supple casing does not give the makers much leeway in how the casing is assembled in the mold. Once in a while, there can be a problem like the one you described, where the casing layers do not overlap as specified.

As you know, we stand behind the product, and replace defective tires, even if they already have been ridden extensively. (Most tire makers’ warranty ends once you have mounted your tires on the rim.) This happens very rarely, so we can be generous with these warranty replacements.

The alternative would be to provide more overlap of the casing layers, and reduce the suppleness and performance of these tires.

Two flats in the first 20 miles of riding my Grand Bois Cypres. (Same tiny piece of glass, didn’t find it the first time). But since then, almost a thousand trouble free miles. Could not be more pleased with the tires.